The present invention generally pertains to electronic communications and is particularly directed to improved systems for determining distances to and locations of predetermined features on a golf course.
Golfers are particularly interested in determining the distance to the pin from their location on the course. In a system described in U.S. Pat. No. 3,868,692 to Woodward et al, separate transmitters are located at each hole on the golf course and transmit RF signals at separate frequencies associated with the respective holes. The golfer carries a portable unit which is tunable to any of the associated frequencies to identify the hole of interest; determines distance to the green based upon the strength of the received signal at the tuned frequency; and displays the determined distance to the golfer.
In another system described in U.S. Pat. No. 4,136,394 to Jones et al, a transponder is mounted at or near the pin on each green on the course and the golfer carries a portable unit which transmits an RF signal to the transponder. The transponder responds to receipt of the RF signal by transmitting an acoustic or sonic signal. The portable unit receives the acoustic or sonic signal; determines distance to the pin based upon the elapsed time between transmission of the RF signal and receipt of the acoustic or sonic signal and displays the determined distance to the golfer.